Bucket fill not working

[rdh61]

If I try to use bucket fill the bucket cursor carries a circle with a slash through it, and I cannot fill the selected layer. I have ensured that the layer I wish to fill is selected, is not locked, and have tried various places withing the area of the layer. In the attached screenshot, I wish to fill the layer called "Background" with another colour. Please see the screenshot. Thank you.

[Ofnuts]

You appear to have a selection (to the left of "Damage") so the bucket-fill won't be enabled until the pointer is in that selection. So remove the selection Select > None.

Probably not the case here, but in case of trouble, displaying the Tool options (tab with easel icon on the left) is more useful than the Images list.